Mold for casting test samples



Jan. 5, 1965 H. V. LAWMASTER MOLD FOR CASTING TEST SAMPLES Filed July 6, 1962 ,5 2 FIG-.5

INVENTOR.

HOLLY V. LAWMASTER BY FULWIDER. PATTON,

RIEBER, LEE 8. UTECHT FIG. 4

ATTORNEYS in which the cylinders are tested to destruction.

United States Patent 3,163,908 MGLD FUR CASTING TEST SAIvELES Holly V. Lawrnaster, 5841 Meinhart Read, Westminster, Calif. Filed July 6, 1962, Ser. No. ZilSJMS 2 Claims. ((Jl. 25-118) The present invention relates generally to molds for casting test samples and more particularly to reusable, sectional plastic molds for casting test cylinders of concrete, gypsum, and like materials. 7

In order to determine the quality and strength of concrete mixes, it is customary to cast test cylinders and to subject the cylinders to various tests at various stage-s of setting and curing, including tests of ultimate streigtli1 tests may he conducted at any time to ascertain the quality of the cement, sand and aggregate used in particular mixes and are panticularly helpful in ascertaining the quality of concrete mixes during progressive stages of large construction jobs.

Heretofore, molds for casting such test cylinders have been made of non-reusable materials such as paperboard whose consumption is comparatively expensive, or of metals which are relatively heavy and have a high initial cost.

According to the present invention, a mold is provided for casting test cylinders of concrete and like materials which is of sectional construction and preferably formed of a lightweight, inexpensive and resusable plastic such as polypropylene. The mold is preferably of two-part sectional construction with the parts interlocked and held together by an overshot sleeve which is preferably also made of a plastic, such as polyethylene, having limited flexibility and providing a snug fit over the mold sections to hold them securely in place.

It is therefore an object of the present invention to provide an improved mold for casting test samples of concrete and similar materials Another object of this invention is the provision of an improved mold for casting test cylinders which is of lightweight, sectional construction formed of a reusable material.

A further object of this invention is the provision of an improved mold for casting test cylinders which is made up of sectional, interlocked parts held together by an overshot sleeve and formed of a lightweight, inexpensive, reusable plastic material.

Theseand other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and the appended drawing, in which: 7

FIGURE 1 is an exploded perspective view of a mold according to the present invention;

FIGURE 2 is a top plan view of the assembled mold;

FIGURE 3 is a vertical seotional view on the line 3-3 of FIGURE 2; v

FIGURE 4 is a detailed view within the circle 4 of FIGURE 2; and

FIGURE 5 is a detailed view within the circle 5 of FIGURE 1 and showing the interlocking means for the mold sections. 7

In the embodiment of the invention selected for illustration in the drawing, there are a pair of mating, complementary mold half sections 11 and 12 which may be exact duplicates or mirror images of each other. In one vertical edge of the section 11 is a groove 13 and projecting from its other vertical edge is a tongue 14. Complementary to these are a groove 15 in one vertical edge of the section 12 and a tongue 15 projecting from the other vertical edge thereof. The tongue 14 is received within the groove 15, as shown in FIGURE 4, and the tongue 16 is'received within the groove 13 when the sections 11 and 12 are assembled to complete the mold so that the sections are properly related or interlocked to form a continuous cylindrical cavity. 1 V i The internal surfaces of the sections 11 and 12 are preferably truly cylindrical while their outer surfaces are given a small taper upwardly so that the outer surface of the assembled mold is slightly frusto-conical.

The bottom of the cylinder 17 is closed by.a plate 18 having an annular nabbet 19. in its upper surface within which is received the bottoms of the mold sections 11 and 12, as shown in FIGURE 3.

Surrounding the mold sections 11 and 12 to hold them together in assembled relation is an overshot plastic sleeve 21 having at least its inner surface of frusto-conical form corresponding to the frusto-conical taper of the outside surface of the assembled sections 11 and 12 so that the 'overshot sleeve 21 fits snugly over, the mold sections to hold them together, as shown in FIGURE 3. Handle grips 22 and'23 may be integrally cast or cemented to the outside of the sleeve 21 to facilitate lifting thereof from the mold sections after a test sample is cast in the mold.

In assembling the mold according to the present invention, the sections 11 and 12 are preferably joined together in the manner shown in FIGURE 4 and placed in the rabbet 19 in the bottom plate 18. The sleeve 21 is then slid downwardly over the sections 11 and 12 to hold them securely together and the parts assume the positions shown in FIGURES 2 and 3 wherein the mold iscomplete and ready for a test sample to be cast therein. The concrete or other mix is poured into the cylindrical cavity 17 and, after it isset, the mold is stripped by grasping the handle holds 22 and 23 and pulling the overshot sleeve 23 upwardly oif from the mold sections 11 and 12 which may be then readily stripped sidewise'from the cast sample by separating the tongues 14, 16 from the grooves 13, 15 as in FIGURE 5. The cast test sample may then be separated from the bottom plate 18 and the sample processed by testing or by further setting or curing to a desired test condition. The mold parts may he immediately reassembled after separation from the cast test sample for the casting of a new sample therein.

The inner surfaces of the sections 11, 12 and the upper surface of the platelet being of smooth plastic material, the concrete or other material cast therein will ordinarily not adhere to the molding surfaces. conventional to place coatings of powder, oil or wax on the mold surfaces if desired, to insure against any possibility of sticking of the mold parts and the cast samples.

The mold parts may be formed of any desired materials but are preferably of inexpensive, durable, lightweight plastic material and, as an example, the sections 11 and i2 and the bottom plate 11 may be formed of polypropylene. formed of inexpensive, lightweight and durable plastic material which has some flexibility to insure a snug fit over the sections 11 and 12, and for these qualities an example is a polyethylene plastic material.

The mold according to the present invention is relatively inexpensive and durable and may be reused many times. It is lightweight for easy manipulation so that the parts may be readily assembled and disassembled in completing the mold and removing the mold parts from the cast sample.

artisans However it is V The overshot sleeve 21 is preferably also mold sections in effecting disassembly of the mold parts from about a cast sample.

While a certain preferred embodiment of the invention has been specifically illustrated'and described, it will be understood that the invention is not limited thereto as many variations will be apparent to those skilled in the art, and the invention is to be given its broadest interpretation within the terms of the following claims.

I claim: a

1. A reusable plastic mold for casting cylindrical concrete'test samples comprising: 7

- a pair of complementary mold sections of plastic material having vertical edges which interengage to define a cylindrical mold cavity, the outer surface of said mold sections being frusto-conioal when said vertical edges are interengaged;

a plastic bottom plate" that interengages the bottom edges of said mold sections when the vertical edges of the latter are interengaged to thereby define the bottom of said mold cavity, 7

and a peripherally continuous overshot plastic sleeve substantially the height of said moldsections and having its inner surface of frusto-conical form corresponding to the frusto-conical taper of the outside 4 e surface of said assembled mold sections, said sleeve fitting snugly over said assembled mold sections to hold the latter together during casting and setting of aconcrete test sample in said mold cavity, said sleeve being thereafter pulled upwardly 011" said mold sections whereby said mold sections and said bottom plate may be removed from said concrete test sample.

2. A mold as set forth in claim 1 wherein the vertical edges of said mold sections are formed with interengaging complementary tongues and grooves.

References Cited by the Examiner UNITED STATES PATENTS 195,062 9/77 Warren et al 18-39 811,310 1/06 Maag 25-127 1,171,641 2/16 Priest 25-127 1,470,008 10/23 Hawkins 18-39 1,591,060 7/26 Sherrerd 25,-127 1,656,886 1/28 Galante 25-121 2,870,515 1/59 Parfitt 25-127 3,021,695 2/62 Voigtmann 25-121 MICHAEL V. BRINDISI, Primary Examiner.

ROBERT F; WHITE, Examiner. 

1. A REUSABLE PLASTIC MOLD FOR CASTING CYLINDRICAL CONCRETE TEST SAMPLES COMPRISING: A PAIR OF COMPLEMENTARY MOLD SECTIONS OF PLASTIC MATERIAL HAVING VERTICAL EDGES WHICH INTERENGAGE TO DEFINE A CYLINDRICAL MOLD CAVITY, THE OUTER SURFACE OF SAID MOLD SECTIONS BEING FRUSTO-CONICAL WHEN SAID VERTICAL EDGES ARE INTERENGAGED; A PLASTIC BOTTOM PLATE THAT INTERENGAGES THE BOTTOM EDGES OF SAID MOLD SECTIONS WHEN THE VERTICAL EDGES OF THE LATTER ARE INTERENGAGED TO THEREBY DEFINE THE BOTTOM OF SAID MOLD CAVITY; AND A PERIPHERALLY CONTINUOUS OVERSHOT PLASTIC SLEEVE SUBSTANTIALLY THE HEIGHT OF SAID MOLD SECTIONS AND HAVING ITS INNER SURFACE OF FRUSTO-CONICAL FORM CORRESPONDING TO THE FRUSTO-CONICAL TAPER OF THE OUTSIDE SURFACE OF SAID ASSEMBLED MOLD SECTIONS, SAID SLEEVE FITTING SNUGLY OVER SAID ASSEMBLED MOLD SECTIONS TO HOLD THE LATTER TOGETHER DURING CASTING AND SETTING OF A CONCRETE TEST SAMPLE IN SAID MOLD CAVITY, SAID SLEEVE BEING THEREAFTER PULLED UPWARDLY OFF SAID MOLD SECTIONS WHEREBY SAID MOLD SECTIONS AND SAID BOTTOM PLATE MAY BE REMOVED FROM SAID CONCRETE TEST SAMPLE. 